At the beginning, NuBi Plus version was commercial but then it became free. It comes with a Spinner – separate effect which is an emulation of the Leslie cabinet. Overall, NuBi has very nice interface, about 30 presets, sounds very good and is very low CPU hungry – there are people who used it on 400 Mhz laptop 🙂 It’s one of the best vst organs available.
NuBi Plus is no longer available as download link but actually you can get it quite easily – just request it from the author. All i know is that attaching NuBi zip file and sending it to someone, who takes time to request it, makes the NuBi developer happy 🙂
ps. If you like NuBi – don’t forget to thank author for it 🙂
update. NuBi Plus is no longer available, instead of you can have NuBi LE version – also pretty nice.
More info: http://www.fxpointaudio.com